This disclosure relates to light towers, and more particularly, although not exclusively, to a method and system for controlling the safety/stability of a mobile light tower.
Mobile light towers are typically used to provide lighting at locations where there are no fixed light sources, and are commonly used, for example, on building/work sites, at sporting/entertainment events, or in other remote locations. Conventional mobile light towers comprise a main body, an extendable mast, and a lighting unit disposed at the distal end of the mast. The main body typically houses a power source powering the lighting unit, and wheels which give the tower its mobility. The extendable mast can be used to raise or lower the lighting unit to a desired position such that appropriate lighting of an area can be achieved.
Whilst the use of mobile light towers is widespread, conventional mobile light towers can suffer from stability issues, which may cause an inherent safety risk. In particular, when the mast of a mobile light tower is in an extended position, the mast may be exposed to high winds, which may cause the mobile light tower to topple when the wind is strong enough. Furthermore, where the mobile light tower is placed in a location where the ground is unstable or uneven, any shift in the ground, or movement of the mobile light tower relative to the ground, may cause the mobile light tower to topple.
The weight of mobile light towers not only provides a safety risk to individuals when it is toppled but also can cause significant damage to the tower itself or adjacent equipment.
It has previously been proposed in GB 2491421 to provide a mobile light tower comprising a wind sensor and a controller for lowering the mast from an extended position in response to high wind speeds. Such a mobile light tower may reduce the risk of the tower toppling only based on the magnitude of the wind speed. It has been found that the direction of the wind speed relative to the lighting rig on the mast can make a significant difference in the toppling load on the mast and thus relatively low wind speeds hitting the lighting equipment front on can provide an equal, or even greater risk of toppling the light tower. Furthermore, this mobile light tower does not reduce the risk of toppling in response to any other unsafe situations, such as, for example, the tower being positioned an incline or a shift in the ground upon which the mobile light tower is located.
The nature of gusting winds means that the tower can become unsafe very quickly, particularly when located on uneven ground.
It may be considered an aim of the invention to provide a lighting tower that offers improved stability. There has now been devised a mobile light tower, a controller for a mobile light tower, and a method of controlling a mobile light tower, which overcome or substantially mitigate the aforementioned and/or other disadvantages associated with the prior art.